General information, not legal advice. For large or long deals, get a lawyer.

For a small monthly sponsorship, a formal contract is usually overkill and often kills momentum. An email that both parties have replied to, containing seven specifics, covers nearly everything that actually goes wrong.

The seven things

1. What they get. Placement name, size, and which pages. "300×250 in the right sidebar, on all article pages."

2. How long. Start and end dates, explicitly. "1 September to 30 September."

3. What it costs and when. "$300, invoiced on the 1st, payable within 14 days."

4. What you're promising on delivery. Either a soft estimate or a firm floor, and say which:

Expected around 20,000 impressions based on recent traffic. This is an estimate, not a guarantee.

Or:

Guaranteed minimum 15,000 impressions. Any shortfall carries into the following month.

Never leave this vague. It is the single most common source of dispute.

5. Creative requirements and deadline. "300×250 JPEG, PNG or WebP, under 200KB, plus destination URL, by the 28th." Add what happens if it is late — usually that the campaign starts when the creative arrives, without extending the end date.

6. What you won't run. A short list. No gambling, no adult content, no political advertising, nothing making claims you consider misleading, and final approval rests with you.

7. How either side ends it. For a monthly deal: "Either of us can decline to renew, with a week's notice before the end of the month."

Things worth adding once you have a few sponsors

Exclusivity, and its price. If a sponsor wants no competitors on the site, that has a cost. Define "competitor" narrowly and in writing, or you will end up in an argument about whether a tangentially related company counts.

Approval turnaround. "Creative approved or rejected within two business days." Protects both sides.

Reporting cadence. "Monthly report sent within three days of month end, plus a live link." Committing to it makes you do it, and doing it is what renews sponsors.

What to leave out

Elaborate liability clauses on a $300 deal. Disproportionate, and they make you look like you are expecting trouble.

Anything about content control. If this is display advertising, they are buying a slot, not influence over your writing. If it is sponsored content, that is a different agreement with different terms.

Automatic renewal with a long notice period. It reads as a trap and small sponsors dislike it. Ask each month instead — you should be talking to them anyway.

Getting paid

For small monthly sponsorships, invoice in advance. It is normal, it removes the awkward chase, and a sponsor unwilling to pay $300 up front is telling you something useful.

If you take card payments through a self-serve checkout, most of this disappears — the money arrives before the campaign starts and there is nothing to chase.

The failure mode to avoid

Not the absence of a contract. It is nothing in writing about delivery. A sponsor who imagined 100,000 impressions and got 20,000 will be unhappy even though you did nothing wrong. Two sentences at the start prevent it entirely.